Robust renewal after extinction of remotely acquired Pavlovian conditioning

Extinguished responses are prone to renew outside the context where extinction occurred. Two experiments compared extinction and renewal following either a 1 day conditioning-to-extinction interval or a 27 day interval. Rats received tone-shock pairings in Context A, and extinction in Context B. Testing occurred in Context A (Experiment 1) or C (Experiment 2). Extinction occurred at a similar rate after both retention intervals. Robust renewal was also observed and was not affected by the conditioning-to-extinction retention interval. Results are discussed with respect to prior research on the timing of extinction, the neurobiology of recent and remote memory retrieval, and translational relevance.